The present invention relates to a gauge developer and more particularly, to an improved gauge developer suitable for use in the sheet-metal work of pipes and tubes to enable workmen to easily record a development elevation of an object by gauging the object at a job site.
In the sheet-metal work of delivery pipes, exhaust pipes and the like, when there is a necessity to plot a development elevation of a complicated pattern in the design and drawing office, this is generally performed by following mechanical drawing or computer plotter techniques and by using instruments in order to obtain the precise developed patterns. It is difficult, however, to acquire a development elevation by gauging the object at a job site. This usually has to be carried out by taking dimensions of the various parts of the object with the help of such instruments as compass, straight rules, tape rule, etc. and also by the use of pencil, card board and scissors to fit the object in order to make a pattern by trial and error. The procedure is therefore tedious and time-consuming, and is less effective.
Intersection markers and templates have previously been devised in an effort to provide a practical device for making the necessary determinations and markings with minimum effort. Examples may be cited in the U.S. Pat. Nos. 2,742,706 to Rushing and 2,761,273 to Barnes. More recently, this author discloses a new and useful gauge developer in the U.S. Pat. No. 4,807,369
With a view to solve the aforesaid problems, the gauge developer, as disclosed in U.S. Pat. No. 4,807,369 and shown here in FIG. 6, includes a flexible strip 1 of soft sheet material, such as rubber, synthetic resin, etc., and a set of insertion pins 3. The strip is provided on one surface thereof along the direction of its length, equally spaced and integrally formed, with a plurality of parallel pin holder portions 2 extending in the direction of the strip breadth. The pins 3 having a length greater than the breadth of the strip are removably inserted in the pin holder portion 2 and, depending on the necessity, there may also be an adhesive layer 8 provided on the back portion of the strip 1. In this gauge developer, however, because of the pin holder portions 2 that project out on the surface of the flexible strip, it has made manufacture somewhat difficult and because of the mold, production of the density of small-pitch pin holders has also been troublesome. Furthermore, insertion pins rely only on the friction of the holder portions for securement in position, and if the hole size becomes greater than the predetermined size owing to a random difference in dimension during the production, the pins would become loose and would thus lead to displacement or even falling off of the pins whereby it results in incapability of obtaining precise development elevations or curves. At the same time, since the pin holder portions are highly protruding on the surface of the strip, if it is desired to place several strips one above the other for use as a multi-layer or stereo gauge block, or for storage in space-saving, there would be much inconvenience. Hence, the disclosed gauge developer presents certain limitations in its uses.
The present invention has for its aim to eliminate the foregoing drawbacks and carry out further innovation over the prior gauge developer.
Accordingly, one object of the present invention is to provide an improved gauge developer suitable for use at a job site in gauging section or curve of any object so as to obtain in a quick and easy way the required development elevation, contour, curve or the shape thereof.
Another object of this invention is to provide a gauge developer having both sides of the developer body formed with even surfaces and the body itself provided with magnetic substances or provided on one side thereof with a coating of magnetic sheet, wherein pin holder portions are recess holes formed by one surface thereof being caved in along the thickness direction, toward the other side where insertion pins when inserted in the holes are held in position by friction of the hole walls and magnetic force from the magnetic body or magnetic layer thereby allowing pins to be maintained in position during use.
A further object of this invention is to provide a gauge developer, several of which can be compactly placed with one above the other in a block form for use in gauging the contour or surface shape of any body having a concavoconvex surface.
In summary, the foregoing and other objects are attained by the provision of a gauge developer including a soft flexible strip having along the length direction of the strip a plurality of tubular pin holder portions which open on the same plane as the surface of the strip and which recesses are caved in from the said surface along the thickness direction of the strip toward the other side and extend along the breadth direction of the strip. In pin holder portions are removably inserted pins having a length greater than the breadth of the strip, and further on one side of the strip, usually on the reverse side of the one where openings are located, there is provided a layer of flexible or rigid magnetic sheet. In another embodiment of the present invention, the strip itself is formed by molding from materials such as synthetic resin having mixed in the interior a magnet powder whereby provision of a magnetic sheet on one side thereof can thus be omitted.
Other objects and advantages of the present invention will become apparent form the following detailed description of the preferred embodiments thereof in connection with the accompanying drawings.